Green technique to make freshwater from wastewater

doi:10.1038/nindia.2018.2 Published online 12 January 2018

Researchers have developed an
eco-friendly technique that uses a specific solution and a thin-film membrane to
extract freshwater from industrial wastewater, seawater and brackish water1.
This technique offers a way to overcome scarcity of freshwater needed for
industry and agriculture.

Freshwater reserves are
steadily depleting across the globe, pushing researchers to devise ways to make
freshwater by treating wastewater and desalinating seawater. Existing
techniques for treating various kinds of wastewater are complex and expensive.

Scientists from the CSIR-Central Salt and Marine Chemicals
Research Institute, Bhavnagar, Gujarat, led by Kamalesh Prasad, invented a
green forward-osmosis process that employs a specific solution made of organic
compounds and a thin-film membrane. They then explored its potential to make
freshwater from brackish water, seawater, dye-contaminated
wastewater and tannery wastewater.

The technique uses a solution
that exhibits low toxicity and remains effective throughout multiple water recovery
cycles. This solution helps extract reusable water from wastewater more
efficiently than the other tested ionic liquids. “Besides making reusable water
from contaminated wastewater, this technique takes us a step closer to
achieving zero liquid waste disposal targets,” says Prasad.